247 nm and 285 nm SiO2 nanoparticles with good dispersibility were synthesized using a Stöber-based solvent varying method, and different structural colors films were obtained by controlling the mixing ratio of the two sized silica nanoparticles. When the proportion of 247 nm SiO2 increased, the color gradually appeared blue-shift, but due to the influence of uncorrelated light scattering, the color of the photonic crystal films are lighter. To solve the problem, the ink was added to the silica suspension, when concentration of the ink increased, the lightness of the film decreased, the saturation increased and the saturation is the highest when the mass fraction of ink was 0.06%. The article made specific analysis on the influence of particle size, mixing ratio and ink content on structural color, the study found that the structural color of the photonic crystal was affected by the particle size and conformed to the Bragg formula, the different mixing ratio changed the average particle size of SiO2, thus formed different colors.The method of producing different structural colors from two particle sizes of SiO2 is simpler and quicker, and can be applied to pigments and coatings for dyeing.